Grinding mill



W. KHLER GRINDING-MILL Aug. 29, 1933- Filed Aug. 17, 1931 2 Sheets-Sheet 1 Willy Hhlen:` y

Aug. 29, 1933. w. KHLER 1,925,069

GRINDING MILL Filed Aug. 17. 1931 2 Sheets-Sheet 2 orneli Patented Aug. 29, 1933 UNITED STATES PATENT OFFICE GRINDING m Willy Khler, Mannhem-Seckenhelm, Germany,

assignor to Joseph Voegele Aktiengesell- Hrm schaft, Mannheim,

Germany, a

Application August 17, 1931, Serial No. 557,613, and in Germany July 14, 1930 6 Claims. (Cl. 83-22) This invention relates to improvements in grinding mills which grind the material in a more or less moist state, varying from a paste to a fairly fluid form and is applicable to the 5 fine grinding of paints, cocoa and the like.

l vided Aproduct than hitherto.

The improved grinding mill also clears thepaste like mass continuously from the walls of the feeding hopper and prevents the formation of cavities in the mass to be ground, thereby preventing irregular action of the mill. Further all impurities contained in the mass to be ground and which cannot pass through the grinding block and roll pair, may be readily removed.

The improved grinding mill of the present invention also tends to a more efficient grinding and trituration, by returning to the bite of the rolls, for another rst-stage grinding, any material which fails to pass the grinding block.

The invention consists in the novel arrangement and construction of the grinding means as fully described hereafter and clearly illustrated by the accompanying drawings.

For the purpose of illustrating my invention, l" show in the accompanying drawings, forms thereof which are at present preferred by me, since the same have been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described.

In the drawings in which like reference characters indicate', like parts Figure 1 is a diagrammatic vertical cross-sectional view of a grinding mill according to one form of the invention taken in a plane at a right angle to the axis of the rolls.

Figure 2 is a diagrammatic vertical cross-sectional view of the same, taken in a plane generally parallel to the axes of the rolls.

Figure 3 is a top` plan view of the same.

Figure 4 is a diagrammatic vertical cross-sectional view of a grinding mill according to another form or embodiment of the invention;- taken in a plane at a right angle to the axis of the rolls.

Figure 5 is a diagrammatic vertical cross-sectional view of the same, taken in a plane generally parallel to the axes of the rolls.

In Figure 1, the main roll B, the secondary roll E and the grinding block C are all mounted in the machine frame A. The rolls E and B coact with each other and constitute the rst grinding stage, and the roll B and grinding block C coact with each other and constitute the second or ne grinding stage. The feed hopper D is located substantially over the main roll B, and feeds the material to the bite of the rolls B and E. Inside the hopper D, the secondary roll E is so located that a narrow space is left between the roll surface and the opposite hopper wall d and this space is indicated by the reference letter e. The secondary roll E is spaced from the grinding block C so as to leave a chamber s. The material which cannot enter the bite of the 'grinding block C and the main roll B, because it is insufficiently reduced in the rst grinding stage between the rolls B and E, collects in the chamber s. This material is then taken up and carried forward by the secondary roll E moving in the direction of the arrow 'y' and carried past the narrow space or constricted outlet e, back into the hopper to be returned through the bite of the 'rolls B and E. In 85 this way when the rolls rotate in the directions of the arrows y and y any material which collects in the space or chamber s is continuously returned by the action of the secondary roll E and passed again through the mill, whilst the material which has been sufficiently reduced in the first grinding stage undergoes a further ne grinding operation in the second grinding stage, that is. between the grinding block C and the main roll B, from whence it is delivered to the delivery hopper H. The secondary roll E inside the hopper D, and continuously moving past the slot or narrow space or constricted outlet e o'f the chamber s serves also continuously to slacken the paste-like material from 10o the hopper wall d, so that the material can readily sink in the hopper D and thus prevent the formation of cavities. For facilitating the adjustment of the bite of the rolls E and B, the journals of the roll E are mounted in an eccentric support G and the latter is connected to levers so that on rotating these levers, the required adjustment may be obtained.

The adjustment of the block C may be e'ected by screws c1. The roll and the block are mounted within the shields K of the machine casing and no s per to pass once more the main roll is rotated by means of the belt pulley M, which in turn transmits its motion by means of the toothed wheels N to the secondary roll E.

In the form or embodiment of the invention shown in Figures 4 and 5, the relative location of the grinding elements is altered; the grinding block C being in this case located generally under the main roll Band the secondary roll E being arranged generally beneath and to one side of the main roll B and to one side of the grinding block C. In this case the space or chamber s is formed between the three grinding elements B, E and C. The material which is not able to pass the fine grinding stage between the roll B and block C, may collect in this chamber and may be transported by the secondary roll E, back to the feed hopper and again to the bite of the rolls B and E. In the modification or form of the invention shown in Figures 4 and 5 a catch plate 9 is located beneath the secondary roll. The catch plate g is brought faisy close to the periphery of the roll E so as to causeV the roll E to engage and transport the material in the chamber s back to the hopper D. A striper plate i may be fitted to engage the surface of the roll B as shown in Figure 4 to slacken off any material clinging to the roll B. The relative positions or setting of the three grinding elements B, C and E can be arranged to suit the purpose for which the mill is being used. It is essential in all cases that the material not sufficiently reduced in the second grinding stage, should be directly taken up by the secondary roll E and returned to the hopthrough the two coacting rolls of the mill. The main roll B is preferably run at a suitably higher peripheral speed than the roll E, as'indicated by the gears N in Figures 2 and 5 and the gear pitch circles N in Figure 4;- said differential peripheral speed of the two rolls being preferable, though the present invention is not dependent thereon.

I am aware that my invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiments to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. A grinding mill including a pair of coacting rolls having their respective axes generally parallel to each other, means for rotating said rolls in opposite directions, respectively, a grinding block coacting with one of said pair of rolls, means coacting with the same roll, beyond the grinding block, for separating from said roll the nally discharged material which has passed said grinding block, hopper means adjacent to and associated with both said rolls for feeding the material in process to the bite of the rolls, and a chamber, bounded at least in part by said rolls and said grinding block and having a constricted outlet adjacent the receding side of the other of said rolls, for causing the latter roll to carry with it and to return to the bite of the rolls, the material which does not pas through, and between the grinding block and said first-mentioned roll.

2. A grinding mill including a pair of coacting rolls having their respective axes generally parallel to each other, means dor rotating said rolls ygrinding both said rolls for feeding block, for separating in opposite directions, a grinding block coacting with one of said pair of rolls, means coacting with the same roll, beyond the grinding block,

for separating from said roll the finally discharged material which has passed with both said rolls for feeding the material in process to the bite of the rolls, and a materialconfining surface associated with the grinding block and the other of said rolls for causing the latter roll to carry with it and to return to the bite of the pair of rolls the material which does not pass through and between the grinding block and said first-mentioned roll.

3. A grinding or triturating mill including a pair of coacting grinding or triturating rolls having their respective axes generally parallel to each other, positive means for holdng said rolls in grinding or triturating relation to each other, means for rotating said rolls in opposite directions, a grinding block coacting with one of said pair of rolls, positive means for holding said block in operative relation to said roll, means coacting with the same roll, beyond the griding block, for separating from said roll the finally discharged material which has passed said grinding block, hopper means adjacent to and associated with both said rolls for feeding the material in process to the bite of the rolls, and a chamber, bounded at least in part by said rolls and said grinding block and having a constricted outlet adjacent the receding side of the other of said rolls, for causing the latter roll to carry with it and to return to the bite of the rolls, the material which does not pass through and between the grinding block and said mst-mentioned roll.

4. A grinding of triturating mill including a pair of coacting grinding or triturating `rolls having their respective axes generally parallel to each other, positive means for holding said rolls in or triturating relation to each other, means for rotating said rolls in opposite directions, a grinding block coacting with one of said pair of rolls, positive means for holding said block in operative relation to said roll, means coacting with the same roll, beyond the grinding block, for separating from'said roll the finally discharged material which has passed said grinding block, hopper means adjacent to and associated with the material in process to the bite of the rolls, and a material-confining surface associated with the grinding block and the other of said rolls and spaced the latter for causing the latter roll to carry with it andtoretumtothebiteofthepairofrollsthe material which does not pas through and be-V tween the grinding block and said first-mentioned roll.

5. Agrinding mill including a pair of coacting rolls having their respective axes generally parallel to each other, means for rotating said rolls in opposite directions, respectively, a grinding block coacting with one of said pair of rolls, means coacting with the same roll, beyond the grinding from said roll and finally discharged material which has said grinding block, and a chamber, bolmded at least in part by said rolls and said grinding block and having a constricted outlet adjacent the receding side of the other of said rolls, for causing the latter roll to carry with bite of the rolls, the material which does not pass through and between the grinding block and said first-mentioned roll.

6.Agrindingmillincludingapairofeoacting said grinding block, hopper means adjacent to and associatedrelatively close to itandtoretumtothe' terial-confining surface associatedv with the grinding block and the other ot ysaid rolls and spaced relatively close to the latter for causing the latter roll to carry with it and to return to the bite of the pair of rolls the material which does not pass through and between the grinding block and said first-mentioned roll.

WILLY KHLER. 

